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3 years ago

The cart is initially at rest. Force

Physics

1 answer:

Oliga [24]3 years ago

5 0

Answer:

$v'=\dfrac{1}{2}v$

Explanation:

Given that,

Initial speed of the cart, u = 0

Let F force is applied to the cart for time $\Delta t$ after which the car has speed v. The force on an object is given by :

F = ma

m is the mass of the cart

We need to find the speed of second cart, if the same force is applied for the same time to a second cart with twice the mass. Force becomes,

$F=\dfrac{mv'}{t}$

$v'=\dfrac{F t}{2m}$

$v'=\dfrac{1}{2}v$

So, the speed of second cart is half of the initial speed of first cart. So, the correct option is (b).

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Will mark brainliest

sweet-ann [11.9K]

Answer: Wouldn't it just be her blocks all walked in an hour added together?

Explanation: 5+2+3+2=12 so 12 blocks an hour?

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3 years ago

Consider the system consisting of the box and the spring, but not Earth. How does the energy of the system when the spring is fu

BabaBlast [244]

Answer:

the energy when it reaches the ground is equal to the energy when the spring is compressed.

Explanation:

For this comparison let's use the conservation of energy theorem.

Starting point. Compressed spring

Em₀ = K_e = ½ k x²

Final point. When the box hits the ground

Em_f = K = ½ m v²

since friction is zero, energy is conserved

Em₀ = Em_f

1 / 2k x² = ½ m v²

v = $\sqrt{ \frac{k}{m} }$ x

Therefore, the energy when it reaches the ground is equal to the energy when the spring is compressed.

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3 years ago

The moons of Mars, Phobos (Fear) and Deimos (Terror), are very close to the planet compared to Earth's Moon. Their orbital radii

tankabanditka [31]

Answer:

$0.2528$

Explanation:

To calculate the period we need the formula:

$T=\frac{2\pi r^{3/2}}{\sqrt{GM}}$

Where $r$ is the radius of the moon, $G$ is the universal constant of gravitation and $M$ is the mass of mars.

The period of Phobos:

$T_{p}=\frac{2\pi r_{p}^{3/2}}{\sqrt{GM}}$

The period of Deimos:

$T_{D}=\frac{2\pi r_{D}^{3/2}}{\sqrt{GM}}$

The ratio of the period of Phobos and Deimos:

$\frac{T_{p}}{T_{D}}=\frac{\frac{2\pi r_{p}^{3/2}}{\sqrt{GM}}}{\frac{2\pi r_{D}^{3/2}}{\sqrt{GM}}}$

$\frac{T_{p}}{T_{D}}=\frac{\sqrt{GM}2\pi r_{p}^{3/2}}{\sqrt{GM}2\pi r_{D}^{3/2}}$

Most terms get canceled and we have:

$\frac{T_{p}}{T_{D}}=\frac{r_{p}^{3/2}}{r_{D}^{3/2}}$

According to the problem

$r_{p}=9,378km\\r_{D}=23,459km$

so the ratio will be:

$\frac{T_{p}}{T_{D}}=\frac{(9,378)^{3/2}}{(23,459)^{3/2}}=\frac{908166.22}{3593058.125}=0.25275$ ≈ $0.2528$

the ratio of the period of revolution of Phobos to that of Deimos is 0.2528

8 0

3 years ago

A communication satellite is in a circular path orbit around Earth. If the speed of the satellite is constant, the net force act

allsm [11]

Answer:

is changing in direction, but constant in magnitude

Explanation:

This question is a bit tricky since the velocity of the satellite is changing, but the speed is constant.

Speed is simply a measure of how fast you are going. It doesn't matter where you're going, just how quickly.

Velocity, on the other hand, does care about which direction you're going. For example, it could be then when you travel right, your velocity is positive, and when you travel left, your velocity is negative. This is the similar for a 2D shape like a circular orbit

Since we know velocity is changing, there must be acceleration which changes that velocity (since acceleration <em>is</em><em> </em>the change in velocity: going from 0 to 60 mph, for example)

Thus, with a non-zero net acceleration, we know that there must be a force that is changing in direction, but constant in magnitude (since the orbit is a circle, and always attracted to the center of the Earth at equal distance).

4 0

3 years ago

The sound absorber is kept at the wall of cinema hall why

Sladkaya [172]

Answer:

because it causes echoes walls are good reflectors of sound

Explanation:

pls mark brainliest ;)

4 0

3 years ago